/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package javax.faces.component;
  
  import java.util.ArrayList;
  import java.util.ConcurrentModificationException;
  import java.util.List;
  import java.util.ListIterator;
  import java.util.Locale;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import javax.el.MethodExpression;
  import javax.el.ValueExpression;
  import javax.faces.FactoryFinder;
  import javax.faces.context.ExternalContext;
  import javax.faces.context.FacesContext;
  import javax.faces.event.AbortProcessingException;
  import javax.faces.event.FacesEvent;
  import javax.faces.event.PhaseEvent;
  import javax.faces.event.PhaseId;
  import javax.faces.event.PhaseListener;
  import javax.faces.lifecycle.Lifecycle;
  import javax.faces.lifecycle.LifecycleFactory;
  import javax.faces.webapp.FacesServlet;
  
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFComponent;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspProperty;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFProperty;
  
  /**
   * Creates a JSF View, which is a container that holds all of the components
   * that are part of the view.
   * <p>
   * Unless otherwise specified, all attributes accept static values or EL
   * expressions.
   * </p>
   * <p>
   * See the javadoc for this class in the <a
   * href="http://java.sun.com/j2ee/javaserverfaces/1.2/docs/api/index.html">JSF
   * Specification</a> for further details.
   * </p>
   */
  @JSFComponent(name="f:view", bodyContent="JSP", tagClass="org.apache.myfaces.taglib.core.ViewTag")
  @JSFJspProperty(name="binding", returnType="java.lang.String", tagExcluded=true)
  public class UIViewRoot extends UIComponentBase
  {
      public static final String COMPONENT_TYPE = "javax.faces.ViewRoot";
      public static final String COMPONENT_FAMILY = "javax.faces.ViewRoot";
  
      public static final String UNIQUE_ID_PREFIX = "j_id";
      private static final int ANY_PHASE_ORDINAL = PhaseId.ANY_PHASE.getOrdinal();
  
      private final Logger logger = Logger.getLogger(UIViewRoot.class.getName());
  
      /**
       * The counter which will ensure a unique component id for every component instance in the tree that
       * doesn't have an id attribute set.
       */
      private long _uniqueIdCounter = 0;
  
      private Locale _locale;
      private String _renderKitId;
      private String _viewId;
  
      // todo: is it right to save the state of _events and _phaseListeners?
      private List<FacesEvent> _events;
      private List<PhaseListener> _phaseListeners;
  
      private MethodExpression _beforePhaseListener;
      private MethodExpression _afterPhaseListener;
  
      private transient Lifecycle _lifecycle = null;
  
      private interface Processor
      {
          void process();
      }
  
      /**
       * Construct an instance of the UIViewRoot.
       */
      public UIViewRoot()
     {
         setRendererType(null);
     }
 
     public void queueEvent(FacesEvent event)
     {
         checkNull(event, "event");
         if (_events == null)
         {
             _events = new ArrayList<FacesEvent>();
         }
         _events.add(event);
     }
 
     public void processDecodes(final FacesContext context)
     {
         checkNull(context, "context");
         process(context, PhaseId.APPLY_REQUEST_VALUES, new Processor()
         {
             public void process()
             {
                 UIViewRoot.super.processDecodes(context);
             }
         }, true);
     }
 
     public void processValidators(final FacesContext context)
     {
         checkNull(context, "context");
         process(context, PhaseId.PROCESS_VALIDATIONS, new Processor()
         {
             public void process()
             {
                 UIViewRoot.super.processValidators(context);
             }
         }, true);
     }
 
     public void processUpdates(final FacesContext context)
     {
         checkNull(context, "context");
         process(context, PhaseId.UPDATE_MODEL_VALUES, new Processor()
         {
             public void process()
             {
                 UIViewRoot.super.processUpdates(context);
             }
         }, true);
     }
 
     public void processApplication(final FacesContext context)
     {
         checkNull(context, "context");
         process(context, PhaseId.INVOKE_APPLICATION, null, true);
     }
 
     public void encodeBegin(FacesContext context) throws java.io.IOException
     {
         checkNull(context, "context");
 
         boolean skipPhase = false;
 
         try
         {
             skipPhase = notifyListeners(context, PhaseId.RENDER_RESPONSE,
                     getBeforePhaseListener(), true);
         }
         catch (Exception e)
         {
             // following the spec we have to swallow the exception
             logger.log(Level.SEVERE,
                     "Exception while processing phase listener: "
                             + e.getMessage(), e);
         }
 
         if (!skipPhase)
         {
             super.encodeBegin(context);
         }
     }
 
     public void encodeEnd(FacesContext context) throws java.io.IOException
     {
         checkNull(context, "context");
         super.encodeEnd(context);
         try
         {
             notifyListeners(context, PhaseId.RENDER_RESPONSE,
                     getAfterPhaseListener(), false);
         }
         catch (Exception e)
         {
             // following the spec we have to swallow the exception
             logger.log(Level.SEVERE,
                     "Exception while processing phase listener: "
                             + e.getMessage(), e);
         }
     }
 
     /**
      * Provides a unique id for this component instance.
      */
     public String createUniqueId()
     {
         StringBuilder bld = __getSharedStringBuilder();
         return bld.append(UNIQUE_ID_PREFIX).append(
                 _uniqueIdCounter++).toString();
     }
 
     /**
      * The locale for this view.
      * <p>
      * Defaults to the default locale specified in the faces configuration file.
      * </p>
      */
     @JSFProperty
     public Locale getLocale()
     {
         if (_locale != null)
         {
             return _locale;
         }
         ValueExpression expression = getValueExpression("locale");
         if (expression != null)
         {
             return (Locale) expression.getValue(getFacesContext()
                     .getELContext());
         }
         else
         {
             Object locale = getFacesContext().getApplication().getViewHandler()
                     .calculateLocale(getFacesContext());
 
             if (locale instanceof Locale)
             {
                 return (Locale) locale;
             }
             else if (locale instanceof String)
             {
                 return stringToLocale((String) locale);
             }
         }
 
         return getFacesContext().getApplication().getViewHandler()
                 .calculateLocale(getFacesContext());
     }
 
     public void setLocale(Locale locale)
     {
         this._locale = locale;
     }
 
     private boolean process(FacesContext context, PhaseId phaseId,
             Processor processor, boolean broadcast)
     {
         if (!notifyListeners(context, phaseId, getBeforePhaseListener(), true))
         {
             if (processor != null)
                 processor.process();
 
             if (broadcast)
             {
                 _broadcastForPhase(phaseId);
             }
         }
         if (context.getRenderResponse() || context.getResponseComplete())
         {
             clearEvents();
         }
         return notifyListeners(context, phaseId, getAfterPhaseListener(), false);
     }
 
     /**
      * Invoke view-specific phase listeners, plus an optional EL MethodExpression.
      * <p>
      * JSF1.2 adds the ability for PhaseListener objects to be added to a UIViewRoot instance,
      * and for "beforePhaseListener" and "afterPhaseListener" EL expressions to be defined
      * on the viewroot. This method is expected to be called at appropriate times, and will
      * then execute the relevant listener callbacks.
      * <p>
      * Parameter "listener" may be null. If not null, then it is an EL expression pointing
      * to a user method that will be invoked.
      * <p>
      * Note that the global PhaseListeners are invoked via the Lifecycle implementation, not
      * from this method here.
      */
     private boolean notifyListeners(FacesContext context, PhaseId phaseId,
             MethodExpression listener, boolean beforePhase)
     {
         boolean skipPhase = false;
 
         if (listener != null
                 || (_phaseListeners != null && !_phaseListeners.isEmpty()))
         {
             PhaseEvent event = createEvent(context, phaseId);
 
             if (listener != null)
             {
                 listener.invoke(context.getELContext(), new Object[]
                 { event });
                 skipPhase = context.getResponseComplete()
                         || context.getRenderResponse();
             }
 
             if (_phaseListeners != null && !_phaseListeners.isEmpty())
             {
                 for (PhaseListener phaseListener : _phaseListeners)
                 {
                     PhaseId listenerPhaseId = phaseListener.getPhaseId();
                     if (phaseId.equals(listenerPhaseId)
                             || PhaseId.ANY_PHASE.equals(listenerPhaseId))
                     {
                         if (beforePhase)
                         {
                             phaseListener.beforePhase(event);
                         }
                         else
                         {
                             phaseListener.afterPhase(event);
                         }
                         skipPhase = context.getResponseComplete()
                                 || context.getRenderResponse();
                     }
                 }
             }
         }
 
         return skipPhase;
     }
 
     private PhaseEvent createEvent(FacesContext context, PhaseId phaseId)
     {
         if (_lifecycle == null)
         {
             LifecycleFactory factory = (LifecycleFactory) FactoryFinder
                     .getFactory(FactoryFinder.LIFECYCLE_FACTORY);
             String id = context.getExternalContext().getInitParameter(
                     FacesServlet.LIFECYCLE_ID_ATTR);
             if (id == null)
             {
                 id = LifecycleFactory.DEFAULT_LIFECYCLE;
             }
             _lifecycle = factory.getLifecycle(id);
         }
         return new PhaseEvent(context, phaseId, _lifecycle);
     }
 
     private void _broadcastForPhase(PhaseId phaseId)
     {
         if (_events == null)
         {
             return;
         }
 
         boolean abort = false;
 
         int phaseIdOrdinal = phaseId.getOrdinal();
         for (ListIterator<FacesEvent> listiterator = _events.listIterator(); listiterator
                 .hasNext();)
         {
             FacesEvent event = listiterator.next();
             int ordinal = event.getPhaseId().getOrdinal();
             if (ordinal == ANY_PHASE_ORDINAL || ordinal == phaseIdOrdinal)
             {
                 UIComponent source = event.getComponent();
                 try
                 {
                     source.broadcast(event);
                 }
                 catch (AbortProcessingException e)
                 {
                     // abort event processing
                     // Page 3-30 of JSF 1.1 spec: "Throw an
                     // AbortProcessingException, to tell the JSF implementation
                     // that no further broadcast of this event, or any further
                     // events, should take place."
                     abort = true;
                     break;
                 }
                 finally
                 {
                     try
                     {
                         listiterator.remove();
                     }
                     catch (ConcurrentModificationException cme)
                     {
                         int eventIndex = listiterator.previousIndex();
                         _events.remove(eventIndex);
                         listiterator = _events.listIterator();
                     }
                 }
             }
         }
 
         if (abort)
         {
             // TODO: abort processing of any event of any phase or just of any
             // event of the current phase???
             clearEvents();
         }
     }
 
     private void clearEvents()
     {
         _events = null;
     }
 
     private void checkNull(Object value, String valueLabel)
     {
         if (value == null)
         {
             throw new NullPointerException(valueLabel + " is null");
         }
     }
 
     private Locale stringToLocale(String localeStr)
     {
         // locale expr: \[a-z]{2}((-|_)[A-Z]{2})?
 
         if (localeStr.contains("_") || localeStr.contains("-"))
         {
             if (localeStr.length() == 2)
             {
                 // localeStr is the lang
                 return new Locale(localeStr);
             }
         }
         else
         {
             if (localeStr.length() == 5)
             {
                 String lang = localeStr.substring(0, 1);
                 String country = localeStr.substring(3, 4);
                 return new Locale(lang, country);
             }
         }
 
         return Locale.getDefault();
     }
 
     /**
      * Defines what renderkit should be used to render this view.
      */
     @JSFProperty
     public String getRenderKitId()
     {
         if (_renderKitId != null)
         {
             return _renderKitId;
         }
         ValueExpression expression = getValueExpression("renderKitId");
         if (expression != null)
         {
             return (String) expression.getValue(getFacesContext()
                     .getELContext());
         }
         return null;
     }
 
     public void setRenderKitId(String renderKitId)
     {
         this._renderKitId = renderKitId;
     }
 
     /**
      * DO NOT USE.
      * <p>
      * This inherited property is disabled. Although this class extends a base-class that
      * defines a read/write rendered property, this particular subclass does not
      * support setting it. Yes, this is broken OO design: direct all complaints
      * to the JSF spec group.
      */
     @Override
     @JSFProperty(tagExcluded=true)
     public void setRendered(boolean state)
     {
         //Call parent method due to TCK problems
         super.setRendered(state);
         //throw new UnsupportedOperationException();
     }
 
     @Override
     public boolean isRendered()
     {
         //Call parent method due to TCK problems
         return super.isRendered();
     }
 
     /**
      * DO NOT USE.
      * <p>
      * Although this class extends a base-class that defines a read/write id
      * property, it makes no sense for this particular subclass to support it.
      * The tag library does not export this property for use, but there is no
      * way to "undeclare" a java method. Yes, this is broken OO design: direct
      * all complaints to the JSF spec group.
      * <p>
      * This property should be disabled (ie throw an exception if invoked).
      * However there are currently several places that call this method (eg
      * during restoreState) so it just does the normal thing for the moment.
      * TODO: fix callers then make this throw an exception.
      * 
      * @JSFProperty tagExcluded="true"
      */
     public void setId(String id)
     {
         // throw new UnsupportedOperationException();
 
         // Leave enabled for now. Things like the TreeStructureManager call this,
         // even though they probably should not.
         super.setId(id);
     }
 
     public String getId()
     {
         // Should just return null. But as setId passes the method on, do same here.
         return super.getId();
     }
 
     /**
      * DO NOT USE.
      * <p>
      * As this component has no "id" property, it has no clientId property either.
      */
     public String getClientId(FacesContext context)
     {
         return super.getClientId(context);
         //Call parent method due to TCK problems
         //return null;
     }
 
     /**
      * A unique identifier for the "template" from which this view was generated.
      * <p>
      * Typically this is the filesystem path to the template file, but the exact
      * details are the responsibility of the current ViewHandler implementation.
      */
     @JSFProperty(tagExcluded = true)
     public String getViewId()
     {
         return _viewId;
     }
 
     public void setViewId(String viewId)
     {
         // It really doesn't make much sense to allow null here.
         // However the TCK does not check for it, and sun's implementation
         // allows it so here we allow it too.
         this._viewId = viewId;
     }
 
     /**
      * Adds a The phaseListeners attached to ViewRoot.
      */
     public void addPhaseListener(PhaseListener phaseListener)
     {
         if (phaseListener == null)
             throw new NullPointerException("phaseListener");
         if (_phaseListeners == null)
             _phaseListeners = new ArrayList<PhaseListener>();
 
         _phaseListeners.add(phaseListener);
     }
 
     /**
      * Removes a The phaseListeners attached to ViewRoot.
      */
     public void removePhaseListener(PhaseListener phaseListener)
     {
         if (phaseListener == null || _phaseListeners == null)
             return;
 
         _phaseListeners.remove(phaseListener);
     }
 
     /**
      * MethodBinding pointing to a method that takes a
      * javax.faces.event.PhaseEvent and returns void,
      * called before every phase except for restore view.
      * 
      * @return the new beforePhaseListener value
      */
     @JSFProperty(stateHolder = true, returnSignature = "void", methodSignature = "javax.faces.event.PhaseEvent", jspName = "beforePhase")
     public MethodExpression getBeforePhaseListener()
     {
         if (_beforePhaseListener != null)
         {
             return _beforePhaseListener;
         }
         ValueExpression expression = getValueExpression("beforePhaseListener");
         if (expression != null)
         {
             return (MethodExpression) expression.getValue(getFacesContext()
                     .getELContext());
         }
         return null;
     }
 
     /**
      * Sets
      * 
      * @param beforePhaseListener
      *            the new beforePhaseListener value
      */
     public void setBeforePhaseListener(MethodExpression beforePhaseListener)
     {
         this._beforePhaseListener = beforePhaseListener;
     }
 
     /**
      * MethodBinding pointing to a method that takes a
      * javax.faces.event.PhaseEvent and returns void,
      * called after every phase except for restore view.
      * 
      * @return the new afterPhaseListener value
      */
     @JSFProperty(stateHolder = true, returnSignature = "void", methodSignature = "javax.faces.event.PhaseEvent", jspName = "afterPhase")
     public MethodExpression getAfterPhaseListener()
     {
         if (_afterPhaseListener != null)
         {
             return _afterPhaseListener;
         }
         ValueExpression expression = getValueExpression("afterPhaseListener");
         if (expression != null)
         {
             return (MethodExpression) expression.getValue(getFacesContext()
                     .getELContext());
         }
         return null;
     }
 
     /**
      * Sets
      * 
      * @param afterPhaseListener
      *            the new afterPhaseListener value
      */
     public void setAfterPhaseListener(MethodExpression afterPhaseListener)
     {
         this._afterPhaseListener = afterPhaseListener;
     }
 
     @Override
     public Object saveState(FacesContext facesContext)
     {
         Object[] values = new Object[8];
         values[0] = super.saveState(facesContext);
         values[1] = _locale;
         values[2] = _renderKitId;
         values[3] = _viewId;
         values[4] = _uniqueIdCounter;
         values[5] = saveAttachedState(facesContext, _phaseListeners);
         values[6] = saveAttachedState(facesContext, _beforePhaseListener);
         values[7] = saveAttachedState(facesContext, _afterPhaseListener);
 
         return values;
     }
 
     @Override
     public void restoreState(FacesContext facesContext, Object state)
     {
         Object[] values = (Object[]) state;
         super.restoreState(facesContext, values[0]);
         _locale = (Locale) values[1];
         _renderKitId = (String) values[2];
         _viewId = (String) values[3];
         _uniqueIdCounter = (Long) values[4];
         _phaseListeners = (List) restoreAttachedState(facesContext, values[5]);
         _beforePhaseListener = (MethodExpression) restoreAttachedState(
                 facesContext, values[6]);
         _afterPhaseListener = (MethodExpression) restoreAttachedState(
                 facesContext, values[7]);
     }
 
     @Override
     public String getFamily()
     {
         return COMPONENT_FAMILY;
     }
 }